<template>
  <div class="swiper-container" ref="imgSwiper">
    <div class="swiper-wrapper">
      <div class="swiper-slide" v-for="(img, index) in imageList" :key="img.id">
        <img
          :src="img.imgUrl"
          :class="{ active: defaultIndex === index }"
          @click="changeDefaultImg(index)"
        />
      </div>
    </div>
    <div class="swiper-button-next"></div>
    <div class="swiper-button-prev"></div>
  </div>
</template>

<script>
import Swiper from "swiper";
export default {
  name: "ImageList",
  props: ["imageList"],
  data() {
    return {
      defaultIndex: 0,
    };
  },
  methods: {
    changeDefaultImg(index) {
      this.defaultIndex = index;
      // 通知zoom我改变了哪张，需要把index传递给zoom
      this.$bus.$emit("changeDefaultImg", index);
    },
  },
  watch: {
    imageList: {
      immediate: true,
      handler(newVal, oldVal) {
        //数据回来了但是，数据回来了我们页面上是需要使用数据来生成div结构
        // div结构还没有生成完成，下面就开始new了，所以，new还是造了

        // this.$nextTick(callback)
        // 这个方法：等待页面最近一次更新完成再去执行回调
        this.$nextTick(() => {
          new Swiper(this.$refs.imgSwiper, {
            slidesPerView:2, //这个代表一个视图能显示几张
            slidesPerGroup:2,//切换的时候，一次切几张
            // 如果需要前进后退按钮
            navigation: {
              nextEl: ".swiper-button-next",
              prevEl: ".swiper-button-prev",
            },
          });
        });
      },
    },
  },
};
</script>

<style lang="less" scoped>
.swiper-container {
  height: 56px;
  width: 412px;
  box-sizing: border-box;
  padding: 0 12px;

  .swiper-slide {
    width: 56px;
    height: 56px;

    img {
      width: 100%;
      height: 100%;
      border: 1px solid #ccc;
      padding: 2px;
      width: 50px;
      height: 50px;
      display: block;

      &.active {
        border: 2px solid #f60;
        padding: 1px;
      }

      // &:hover {
      //   border: 2px solid #f60;
      //   padding: 1px;
      // }
    }
  }

  .swiper-button-next {
    left: auto;
    right: 0;
  }

  .swiper-button-prev {
    left: 0;
    right: auto;
  }

  .swiper-button-next,
  .swiper-button-prev {
    box-sizing: border-box;
    width: 12px;
    height: 56px;
    background: rgb(235, 235, 235);
    border: 1px solid rgb(204, 204, 204);
    top: 0;
    margin-top: 0;
    &::after {
      font-size: 12px;
    }
  }
}
</style>